The present invention is directed to an ink application device for a rotary printing press. The printing ink and at least a portion of the doctor blade arrangement are heated.
A rotogravure inking device has become known from EP 655 328 B1. A doctor device is arranged remote from the ink duct and closely in front of the printing zone in order to prevent the premature drying of the solvent-containing printing ink.
DE 93 10 680 U1 describes an arrangement for setting the temperature of printing ink in the inking device of a printing press. No doctor device resting against a roller is provided there.
WO 98/50233 A shows a rotogravure inking device. A doctor blade is arranged below a horizontal line extending through the axis of rotation of the forme cylinder.
DE 197 36 339 A1 describes a temperature-adjusting device for a screen roller with a doctor blade.
DE 42 05 713 C2 discloses rotogravure ink, which is used for printing in a warmed state and which dries by cooling.
The object of the present invention is directed to providing an ink application device for a forme cylinder used with rotogravure printing. Printing inks, whose working temperatures lie above the ambient temperature, can be used for printing.
In accordance with the present invention, this object is attained by providing printing ink in an ink trough of an ink application device for rotogravure printing on a rotary printing press. The printing ink in the ink trough has a working temperature higher than ambient. At least parts of a doctor blade arrangement in the ink application device are capable of being heated. A contact line of a doctor blade of the doctor blade arrangement is below a horizontal line that extends through the axis of rotation of a forme cylinder in the rotary printing press.
The advantages which can be obtained by the present invention rest, in particular, in that removal of the printing ink from the roller, or from the forme cylinder, by use of a doctor blade, takes place in the immediate vicinity of the ink level of the printing ink in the ink trough. This results in a short distance for the printing ink, removed by a doctor blade from the roller to be inked, to fall. In this way, faults because of splashes when the removed ink drops into the ink duct, are held to a minimum. An ink foam, which would otherwise be created, is also prevented, so that soiling of the inking device does not occur.
Because of the ability to preset the temperature of the printing ink, it is possible to also use so-called hot-tec printing inks for rotogravure printing. In this context, see DE 42 05 713 C2. These printing inks are applied without solvents at a temperature of approximately 100 to 110xc2x0 C. to the material to be printed.
Only a negligible heat loss is noted because of a compact arrangement of the parts of the inking device which come into contact with the hot-tec printing ink.